Compressed gas circuit interrupter having a closed-cycle high pressure heating circulation

ABSTRACT

Compressed-gas circuit breaker including piping for breaker, wherein the temperature is maintained substantially constant by surrounding the entire length of said piping unit with an extinguishing gas feed piping in which a closed circuit forced circulation of heated gas is maintained.

United States Patent [151 3,703,619 Henry [4 1 Nov. 21, 1972 1541 COMPRESSED GAS CIRCUIT 61 References Cited INTERRUPTER HAVING A CLOSED- CYCLE HIGH PRESSURE HEATING UNITED STATES PATENTS CIRCULATION 2,890,312 6/1959 Forwaldm, ..200/148 B 3,009,042 11/1961 Schrameck et al.....200/148 B [72] Invent ELE 3,129,309 4/1964 McKeough et al. ....200/l48 B 7 3,214,544 10/1965 Leeds ..200/148 E [73] Assignee: Merlin Gerin, Societe Anonyme, 1

Grenoble, France FOREIGN PATENTS OR APPLICATIONS [22] Filed: July 6, 1970 1,206,229 8/1959 France ..200/148 E 1,142,937 1/1963 Germany ..200/148 D [211 App! 52428 878,658 10/1961 Great Britain ..200/148 D Related US. Application Data 1,133,067 11/1968 Great Britain ..200/ 148 E [63] (2IZ1niu9n6u7atfJna:r1lr:1-g::j of Ser.'No. 667,687, Oct. ri Examiner Roben S Macon Attorney-Stevens, Davis, Miller and Mosher [30] N Ftgrelggn6 6App11(;1l0l\ Priority Data 6682451 ABSTRACT 0v. tame Compressed-gas circuit breaker including piping for 52 U.S. c1 ..200/14s E, 200/ 148 B breaker Wherei" the temperature is maintained [51] Int. Cl. ..H0lh 33/57 Stantially constant by Surrounding the entire length of 53 said piping unit with an extinguishing gas feed. piping Field of Search....200/148 E; 148 D, 148,148 B in which a closed circuit forced circulation of heated gas is maintained.

8 Claims, 6 Drawing Figures II II 1 .L

H 82 i 3 1o 84 111 III .1. .L

COMPRESSED GAS CIRCUIT INTERRUPTER HAVING A CLOSED-CYCLE HIGH PRESSURE HEATING CIRCULATION high potential, high pressure tank means disposed in the vicinity of said arc-extinguishing means, for delivering a high pressure blast gas to said arc-extinguishing means while high pressure low potential tank means, generally disposed in the vicinity of the ground and at or near earth potential, feed said high pressure high potential tank means through gas supply conduit means extending from the low to the high potential zones of the breaker. I v p Generally, in circuit breakers of this type, a control gas conduit means connects a control valve means to a gas operated control means which is disposed near to the arc-extinguishing means in the high potential zone of the breaker. The control means is for moving the breaker contacts relative to each other and the control valve means, which may be manually, electrically, hydrolically, or otherwise operated and will be at or close to earth potential.

The gas control and gas supply conduit means mu be distinct and cannot consist of a single conduit because the control-conduit means carries gas of at least two different pressures in order to operate the arcextinguishing means, such as a pair of separable contacts, in their opening and closing movements. On the other hand, the gas supply conduit means conducts a pressurized gas, at substantially a constant pressure to said high potential tank means so that the breaker is always ready to operate. The extinguishing gas, however, such as sulfer hexafluoride (SP6), may be different from the control gas (such as air).

Since sulfer hexafluoride liquefies at the pressure of the high pressure tank means which is, for instance, 14 bars) at a temperature close -to 32 F, it has already been proposed to prevent this liquefaction by means of heating resistorsdisposed in thesmain tankmeans at earth potential.

The control gas also runs the risk of liquifying, but it is practically impossible to prevent this dual pressure gas from liquefying by means of heating resistors. The

presence of liquid in the control conduit is undesireable since it may lead to flash-over and faulty operation.

It is an object of the invention to provide a circuit breaker of the type mentioned in which the temperature fluctuations of the control gas are minimized to exclude problems resulting from the liquefying of said gas.

It is another object of the invention to provide a circuit breaker having a new and improved gas supply and gas control conduit means providing for easy temperature control of said gases.

Still another object of the invention is to provide an improved circuit breaker having a gas conduit means which is simple and reliable in operation and relatively inexpensive to manufacture.

These and other objects and advantages will be apparent from the following description which refers to the accompanying drawings in which:

FIG. 1 is a cross-sectional elevation of an embodiment of the invention;

FIG. 2 is a magnified cross-sectional plan view taken along the line 2-2 of FIG. 1;

FIG. 3 is a magnified cross-sectional plan view taken along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged cross-sectional view of a gas operated valve member, according to the invention;

FIG. 5 is an enlarged cross-sectional 'view of another gas operated valve member, according to the invention, and

FIG. 6 is an enlarged cross-sectional view of a control valve according to the invention.

Referring now to'the drawings, the compressed gas circuit breaker comprises a grounded metal tank 10, which is supported by a base member 12 supported on the ground and housing essentially a high pressure low potential storage tank 14, a compressor 16, pump means 18 and electrically operated control valve means 20. The compressor 16 recompresses low pressure areextinguishing gas (such as sulfur hexafluoride, SF taken from the exhaust tank 10 through pipe 22 to supply high pressure gas through a pipe 24 to the main high pressure tank 14. An electric heating resistor 26 extends into tank 14 to prevent liquefaction of said gas and is controlled by suitable control means (not shown) such as by a thermostat as a function of temperature.

The high potential or live parts of the circuit breaker are located in tank 10 and comprise essentially a pair of electrically series connected arc-extinguishing chambers, 28 and 30. Each chamber, one of which will only be described, the other chamber being identical thereto, consists of a vertically extending cylindrical inv sulator 32 containing said high-pressure arc-extinguishing gas and which houses a pair of separable hollow contact members 34, 36. The housing 32 of each chamber 28, 30 constitutes a high pressure high potential tank containing an arc-extinguishing gas such as sulfur hexafluoride, pressurized for instance to 14 bars.

A housing 42 projects into each chamber 32 to support v control piston 54 which is slidably mounted in a cylindrical housing 56. A small calibrated passage 58 extends through the valve member 50, the stem 52 and the piston 54 to permit pressurizing the back side of the piston 54. A compression spring 60 biases the piston in one direction. The valve member 50 is mounted in a housing 62 which communicates freely through an orifree 64 with the housing 66 in which slides a piston 68 which controls, through stem'70, the movement of the exhaust valve member 46. The pilot valve member 50 can temporarily admit pressurized gas to the active side (top side in FIG. 4) of the piston 68 to thereby open valve 46 against the action of a-compression spring 72 immediately after a rise in pressure in a control conduit 74,but, valve 50 moves after a short time to its original position (left hand position in FIG. 4) as gas pressure builds up behind the piston 54 because of gas flow through passage 58. This then vents the active side of piston 68 through the orifice 64 and a second orifice 76 of housing 62 to the low pressure tank 10.

identical assembly as that of exhaust valve 44 and pilot valve 48 is disposed at the other end of the chambers 28 and 30 to permit venting to the low pressure tank l of the interior of the tubular movable contacts Such contact 36 is integral with a driving piston 78 and biased. towardsits closed circuit position by a compressionspring 80. The back side of piston 78 can be selectively vented to the low pressure tank or can be fed pressurized gas from the chambers by means of a control valve 82 (FIG. 5). Each control valve 82 has a valve member 84 which is moved through a stem 86 by 'a piston 88. The piston 88 is biased by a compression spring 90 and its active side is exposed to the pressure of the control conduit 74. The valve member 84 is movable within a'small' chamber 92 which communicates throughport 94 with the interior of low pressure vessel 10, through passage 96 with the high pressure in the associated chamber, and through passage 98 with the region behind the piston 78, the opposite of which is continuously exposed to the high pressure in the chamber. Thus, pressurizing of the control conduit 74 causes the piston 88 and valve member 84 to move against the action of the compression spring '90 to close the passage 96 and to vent the region behind the piston 78 through passage 98 and port 94 to a low pressure zone so that the piston 78 moves the movable'contact 36 to its open circuit position. It is seen that venting of the control conduit 74 causes the valve member 84 to close the port 94 and pressurize the region behind the piston 78 through passages 96 and 98 so as to permit closing of the movable'contact 36 under the influence of biasing spring 80.

, To permit the opening and closing of the contacts, the double acting control valve 20 having valve members 100 and 102integral with an electromagnetically operated stem member 104 includes a valve body communicating through. a tube 106 with the high pressure gas of themain tank 14; through a tube 108 with the low pressure gas in vessel 10; andthrough pipe 110 with the interior of the control conduit 74. A compression spring 112 biases the valve members 100 and 102 to one of their end positions, a solenoid coil 114 causing, when energized, the control valve members 100 and 102 to move to their opposite end position, against the action of spring 112.

It will now be obvious, that following the pressurizing of control conduit 74, by energizing of coil 114, the contacts in the arc-extinguishing chambers 28 and 30 open to draw an are between their opposed end portions whereupon the exhaust valves 44 open for a short time to permit blasting of the arc through the interior of contacts 34 and 36 and exhausting of the blast gases through the exhaust valves 44 to the interior of low pressure vessel 10. Immediately after exhausting, the movement of valve members 50'of the pilot valve 48 causes the valve members 46 to reclose whereas the contacts remain in their open circuit position in the high pressure chambers 28 and 30. It is to be noted that the compressor 16 recompresses regularly the low pressure exhaust gases taken from vessel 10 to deliver high pressure gas to main tank 14 and thus to the chambers 28 and 30.

v To effect closing of the contacts, solenoid coil 114 is de-energized and control conduit 74 is vented to the low pressure vessell0, permitting 'springs to close the movable contacts 36 and bring pilot valve members 50 to their initial position in sealing relation against ports 76 without moving valve members 46 which remain closed. I a I It is noted that the live parts of the circuit breaker are supported by vessel 10 through'suit'able insulators and tie rods 122.

According to an important featureof the invention the control conduit 74 connecting the control valve 20 to the pilot valves 48 and to the contact movement control valves 82 is surrounded over at least a substantial part of its length by a gas supply conduit 126 so as to constitute a composite conduit which is constituted by two radially spaced apart concentric conduits. Conduit 126 supplies high pressure arc-extinguishing gas taken from tank 14 through a pipe l28-to the upper end of chamber 28. The interior of chambers 28 and 30 communicate through a pipe 130, which can be of electrically conductive material to assure the series connection of the current carrying parts of these chambers. A return pipe 132 connects the interior of chamber 30 to the pump 18 and the return path for the high pressure gas is completed by a pipe 134 connecting the pump 18 to the interior of main storage tank 14. v

In order to have identical time responses of thegas operated control devices of the chambers 28 and 30, the lower portion 74' of the control gas conduit 74 connected to the valve 20 discharges into a manifold 138 connected to different branch conduits 74 and in particular to inner coaxial control gas conduit 74" which feeds the lower pilot valve 48.

Conductors 140 and 142, extending through portion 144 and 146 respectively of the vessel 10, are electrically connected to the terminals of the chambers 28 and 30.

It will now be apparent, that pump 18 maintains a forced closed cycle circulation of high pressure arcextinguishing gas in the direction of the arrows through pipe 134, tank 14, pipe 128, outer conduit 126 (which envelopes manifold 138); chamber 28, pipe 130, chamber 30 and pipe 132. The gas is heated by resistor 26 and flows along the outer wall of the control conduit 74 over a substantial part of its length so that the noncirculating control gas contained with in conduit 74 is sufficiently heated to prevent liquefying thereof.

What is claimed is:

1. Compressed gas circuit breaker of the kind having gas blast type arc-extinguishing means, comprising in combination: high pressure low potential storage tank means, at least one further high pressure tank means disposed in the vicinity of said arc-extinguishing means, gas supply conduit means supplying high pressure arcextinguishing blast gas from said high pressure low potential storage tank means to said further high pressure tank means, control 'valve means disposed in the vicinity of said high pressure low. potential storage tank means, gas operated control means disposed in the vicinity of said arc-extinguishing means to control said arc-extinguishing means, control gas conduit means surrounded over at least a substantial part of its length by said gas supply conduit means and connecting said control valve means to said gas operated control means, said control valve means controlling the pressure in said control gas conduit means to operate said gas operated control means, further gasconduit means connecting said further high pressure tank means to said high pressure low potential storage tank means, heating means to heat said high-pressure arc-extinguishing blast gas and pump means to establish a forced closed-cycle continuous circulation of said high pressure arc-extinguishing blast gas between said low potential tankmeans and said further tank means through said further gas conduit means and through said gas supply conduict means to continually heat the control gas in said part of said control gas conduit means.

2. Compressed gas circuit breaker according to claim 1, wherein said pump means are disposed in said further gas conduit means.

3. Compressed gas circuit breaker according to claim 1, wherein said heating means is disposed in said high pressure low potential storage tank means.

4. Compressed gas circuit breaker of the kind having gas blast type arc-extinguishing means comprising storage tank means spaced apart a distance from said arc-extinguishing means and containing a high pressure arc-extinguishing gas, gas supply conduit means to supply high pressure arc-extinguishing gas from said storage tank means to said arc-extinguishing means, gas operated control means to operate said arc-extinguish ing means and comprising control gas conduit means substantially surrounded by said gas supply conduit means, heating means to heat said high pressure areextinguishing gas, and circulation means to establish a high pressure continuous gas circulation in said gas supply conduit means through said gas supply conduit means to permit continuous heating of the control gas in said control gas conduit means.

5. Compressed gas circuit breaker according to claim 4, further comprising high pressure gas return conduit means connecting said arc-extinguishing means to said storage tank means, said circulation means establishing a closed-cycle high pressure gas circulation of said areextinguishing gas in said gas supply conduit means and said return conduit means.

6. Compressed gas circuit breaker comprising a plurality of longitudinally aligned, electrically series connected arc-extinguishing chambers, containing a high pressure arc-extinguishing gas, separable contact means in each chamber, each chamber including gas operated control means to control the movement of said contact means, control gas conduit means connected to said control means of said chambers, control to heat said high pressure arc-extinguishing gas and means to establish a continuous forced circulation of said high pressure arc-extinguishing gas in said path through said gas supply conduit means to permit heating of the control gas in said control gas conduit means independently of the operation of said contact means,

7. ompressed gas circuit breaker according to claim 6, further comprising exhaust valve means associated with said chambers, gas operated exhaust valve control means to control said exhaust valve means, said control gas conduit .means being connected to said exhaust valve control means.

8. Compressed gas circuit breaker of the kind having at least one arc-extinguishing chamber containing a high pressure arc-extinguishing gas and separable contact means in said chamber, said chamber including gas operated control means to control the movement of said contact means, control gas conduit means operatively connected to said control means, control valve means operatively connected to said control gas conduit means to operate said control means by controlling the pressure within said control gas conduit means, high pressure conduit means connected to said chamber, a portion of said high pressure conduit means surrounding said control gas conduit means over at least a substantial part of the length thereof between said control valve means and said control means, pump means in said high pressure conduit means, and heat means to heat said high pressure gas, said high pressure conduit means being arranged in closed loop configuration such that said pump means establishes a forced closed cycle continuous circulation of said high pressure arc-extinguishing gas in said high pressure conduit means and in said arc-extinguishing chamber thereby to cause the heated high pressure arc-extinguishing gas to heat said part of said control gas conduit means independently of the operation of said control means. 

1. Compressed gas circuit breaker of the kind having gas blast type arc-extinguishing means, comprising in combination: high pressure low potential storage tank means, at least one further high pressure tank means disposed in the vicinity of said arc-extinguishing means, gas supply conduit means supplying high pressure arc-extinguishing blast gas from said high pressure low potential storage tank means to said further high pressure tank means, control valve means disposed in the vicinity of said high pressure low potential storage tank means, gas operated control means disposed in the vicinity of said arc-extinguishing means to control said arc-extinguishing means, control gas conduit means surrounded over at least a substantial part of its length by said gas supply conduit means and connecting said control valve means to said gas operated control means, said control valve means controlling the pressure in said control gas conduit means to operate said gas operated control means, further gas conduit means connecting said further high pressure tank means to said high pressure low potential storage tank means, heating means to heat said high-pressure arc-extinguishing blast gas and pump means to establish a forced closed-cycle continuous circulation of said high pressure arc-extinguishing blast gas between said low potential tank means and said further tank means through said further gas conduit means and through said gas supply conduict means to continually heat the control gas in said part of said control gas conduit means.
 1. Compressed gas circuit breaker of the kind having gas blast type arc-extinguishing means, comprising in combination: high pressure low potential storage tank means, at least one further high pressure tank means disposed in the vicinity of said arcextinguishing means, gas supply conduit means supplying high pressure arc-extinguishing blast gas from said high pressure low potential storage tank means to said further high pressure tank means, control valve means disposed in the vicinity of said high pressure low potential storage tank means, gas operated control means disposed in the vicinity of said arc-extinguishing means to control said arc-extinguishing means, control gas conduit means surrounded over at least a substantial part of its length by said gas supply conduit means and connecting said control valve means to said gas operated control means, said control valve means controlling the pressure in said control gas conduit means to operate said gas operated control means, further gas conduit means connecting said further high pressure tank means to said high pressure low potential storage tank means, heating means to heat said high-pressure arc-extinguishing blast gas and pump means to establish a forced closed-cycle continuous circulation of said high pressure arc-extinguishing blast gas between said low potential tank means and said further tank means through said further gas conduit means and through said gas supply conduict means to continually heat the control gas in said part of said control gas conduit means.
 2. Compressed gas circuit breaker according to claim 1, wherein said pump means are disposed in said further gas conduit means.
 3. Compressed gas circuit breaker according to claim 1, wherein said heating means is disposed in said high pressure low potential storage tank means.
 4. Compressed gas circuit breaker of the kind having gas blast type arc-extinguishing means comprising storage tank means spaced apart a distance from said arc-extinguishing means and containing a high pressure arc-extinguishing gas, gas supply conduit means to supply high pressure arc-extinguishing gas from said storage tank means to said arc-extinguishing means, gas operated control means to operate said arc-extinguishing means and comprising control gas conduit means substantially surrounded by said gas supply conduit means, heating means to heat said high pressure arc-extinguishing gas, and circulation means to establish a high pressure continuous gas circulation in said gas supply conduit means through said gas supply conduit means to permit continuous heating of the control gas in said control gas conduit means.
 5. Compressed gas circuit breaker according to claim 4, further comprising high pressure gas return conduit means connecting said arc-extinguishing means to said storage tank means, said circulation means establishing a closed-cycle high pressure gas circulation of said arc-extinguishing gas in said gas supply conduit means and said return conduit means.
 6. Compressed gas circuit breaker comprising a plurality of longitudinally aligned, electrically series connected arc-extinguishing chambers, containing a high pressure arc-extinguishing gas, separable contact means in each chamber, each chamber including gas operated control means to control the movement of said contact means, control gas conduit means connected to said control means of said chambers, control valve means connected to said control gas conduit means to control the pressure therein, gas supply conduit means to supply said high pressure arc-extinguishing gas to one of said chambers, said gas supply conduit means surrounding said control gas conduit means over at least a substantial part of the length thereof between said control valve means and said chambers, further conduit means connecting said chambers pneumatically in series to constitute with said gas supply conduit means and said chambers a closed loop high pressure arc-extinguishing gas circulation path, heating means to heat said high pressure arc-extinguishing gas and means to establish a continuous forced circulation of said high pressure arc-extinguishing gas in said path through said gas supply conduit means to permit heating of the control gas in said control gas conduit means independently of the operation of said contact means.
 7. Compressed gas circuit breaker according to claim 6, further comprising exhaust valve means associated with said chambers, gas operated exhaust valve control means to control said exhaust valve means, said control gas conduit means being connected to said exhaust valve control means. 